From f262caf1f5d0a78a8d6917bb04d8ee403b2157a9 Mon Sep 17 00:00:00 2001
From: HFO4 <912394456@qq.com>
Date: Fri, 13 Dec 2019 20:46:11 +0800
Subject: [PATCH] Feat: download file and get file downloading session

---
 models/migration.go             |  3 +-
 pkg/filesystem/file.go          | 42 ++++++++++++++++++++++++++-
 pkg/filesystem/filesystem.go    |  2 ++
 pkg/filesystem/local/handler.go | 28 ++++++++++++++++++
 pkg/filesystem/upload_test.go   |  4 +++
 pkg/serializer/error.go         |  4 +++
 routers/controllers/file.go     | 23 ++++++++++++---
 routers/router.go               |  8 ++++--
 service/explorer/file.go        | 50 ++++++++++++++++++++++++++++-----
 service/explorer/objects.go     |  2 +-
 10 files changed, 149 insertions(+), 17 deletions(-)

diff --git a/models/migration.go b/models/migration.go
index 35178cd..fab53bc 100644
--- a/models/migration.go
+++ b/models/migration.go
@@ -97,7 +97,8 @@ solid #e9e9e9;"bgcolor="#fff"><tbody><tr style="font-family: 'Helvetica Neue',He
 		{Name: "ban_time", Value: `10`, Type: "storage_policy"},
 		{Name: "maxEditSize", Value: `100000`, Type: "file_edit"},
 		{Name: "oss_timeout", Value: `3600`, Type: "timeout"},
-		{Name: "local_archive_timeout", Value: `30`, Type: "timeout"},
+		{Name: "archive_timeout", Value: `30`, Type: "timeout"},
+		{Name: "download_timeout", Value: `30`, Type: "timeout"},
 		{Name: "allowdVisitorDownload", Value: `false`, Type: "share"},
 		{Name: "login_captcha", Value: `0`, Type: "login"},
 		{Name: "qq_login", Value: `0`, Type: "login"},
diff --git a/pkg/filesystem/file.go b/pkg/filesystem/file.go
index bee9d69..4cabbc7 100644
--- a/pkg/filesystem/file.go
+++ b/pkg/filesystem/file.go
@@ -8,6 +8,7 @@ import (
 	"github.com/HFO4/cloudreve/pkg/util"
 	"github.com/juju/ratelimit"
 	"io"
+	"strconv"
 )
 
 /* ============
@@ -105,8 +106,8 @@ func (fs *FileSystem) GetContent(ctx context.Context, path string) (io.ReadSeeke
 			return nil, ErrObjectNotExist
 		}
 		fs.FileTarget = []model.File{*file}
-		ctx = context.WithValue(ctx, fsctx.FileModelCtx, file)
 	}
+	ctx = context.WithValue(ctx, fsctx.FileModelCtx, fs.FileTarget[0])
 
 	// 将当前存储策略重设为文件使用的
 	fs.Policy = fs.FileTarget[0].GetPolicy()
@@ -173,6 +174,45 @@ func (fs *FileSystem) GroupFileByPolicy(ctx context.Context, files []model.File)
 	return policyGroup
 }
 
+// GetDownloadURL 创建文件下载链接
+func (fs *FileSystem) GetDownloadURL(ctx context.Context, path string) (string, error) {
+	// 找到文件
+	if len(fs.FileTarget) == 0 {
+		exist, file := fs.IsFileExist(path)
+		if !exist {
+			return "", ErrObjectNotExist
+		}
+		fs.FileTarget = []model.File{*file}
+	}
+
+	ctx = context.WithValue(ctx, fsctx.FileModelCtx, fs.FileTarget[0])
+
+	// 将当前存储策略重设为文件使用的
+	fs.Policy = fs.FileTarget[0].GetPolicy()
+	err := fs.dispatchHandler()
+	if err != nil {
+		return "", err
+	}
+
+	// 生成下載地址
+	siteURL := model.GetSiteURL()
+	ttl, err := strconv.ParseInt(model.GetSettingByName("download_timeout"), 10, 64)
+	if err != nil {
+		return "", serializer.NewError(serializer.CodeInternalSetting, "无法获取下载地址有效期", err)
+	}
+	source, err := fs.Handler.GetDownloadURL(
+		ctx,
+		fs.FileTarget[0].SourceName,
+		*siteURL,
+		ttl,
+	)
+	if err != nil {
+		return "", serializer.NewError(serializer.CodeNotSet, "无法获取下载地址", err)
+	}
+
+	return source, nil
+}
+
 // GetSource 获取可直接访问文件的外链地址
 func (fs *FileSystem) GetSource(ctx context.Context, fileID uint) (string, error) {
 	// 查找文件记录
diff --git a/pkg/filesystem/filesystem.go b/pkg/filesystem/filesystem.go
index acb47a0..8428557 100644
--- a/pkg/filesystem/filesystem.go
+++ b/pkg/filesystem/filesystem.go
@@ -32,6 +32,8 @@ type Handler interface {
 	Thumb(ctx context.Context, path string) (*response.ContentResponse, error)
 	// 获取外链地址，url
 	Source(ctx context.Context, path string, url url.URL, expires int64) (string, error)
+	//获取下载地址
+	GetDownloadURL(ctx context.Context, path string, url url.URL, expires int64) (string, error)
 }
 
 // FileSystem 管理文件的文件系统
diff --git a/pkg/filesystem/local/handler.go b/pkg/filesystem/local/handler.go
index 9281c66..1019c42 100644
--- a/pkg/filesystem/local/handler.go
+++ b/pkg/filesystem/local/handler.go
@@ -6,6 +6,7 @@ import (
 	"fmt"
 	model "github.com/HFO4/cloudreve/models"
 	"github.com/HFO4/cloudreve/pkg/auth"
+	"github.com/HFO4/cloudreve/pkg/cache"
 	"github.com/HFO4/cloudreve/pkg/conf"
 	"github.com/HFO4/cloudreve/pkg/filesystem/fsctx"
 	"github.com/HFO4/cloudreve/pkg/filesystem/response"
@@ -15,6 +16,7 @@ import (
 	"net/url"
 	"os"
 	"path/filepath"
+	"time"
 )
 
 // Handler 本地策略适配器
@@ -127,3 +129,29 @@ func (handler Handler) Source(ctx context.Context, path string, url url.URL, exp
 	finalURL := url.ResolveReference(signedURI).String()
 	return finalURL, nil
 }
+
+func (handler Handler) GetDownloadURL(ctx context.Context, path string, url url.URL, ttl int64) (string, error) {
+	file, ok := ctx.Value(fsctx.FileModelCtx).(model.File)
+	if !ok {
+		return "", errors.New("无法获取文件记录上下文")
+	}
+
+	// 创建下载会话，将文件信息写入缓存
+	downloadSessionID := util.RandStringRunes(16)
+	err := cache.Set("download_"+downloadSessionID, file, int(ttl))
+	if err != nil {
+		return "", serializer.NewError(serializer.CodeCacheOperation, "无法创建下載会话", err)
+	}
+
+	// 签名生成文件记录
+	signedURI, err := auth.SignURI(
+		fmt.Sprintf("/api/v3/file/download/%s", downloadSessionID),
+		time.Now().Unix()+ttl,
+	)
+	if err != nil {
+		return "", serializer.NewError(serializer.CodeEncryptError, "无法对URL进行签名", err)
+	}
+
+	finalURL := url.ResolveReference(signedURI).String()
+	return finalURL, nil
+}
diff --git a/pkg/filesystem/upload_test.go b/pkg/filesystem/upload_test.go
index adf98f9..50fa48b 100644
--- a/pkg/filesystem/upload_test.go
+++ b/pkg/filesystem/upload_test.go
@@ -46,6 +46,10 @@ func (m FileHeaderMock) Source(ctx context.Context, path string, url url.URL, ex
 	args := m.Called(ctx, path, url, expires)
 	return args.Get(0).(string), args.Error(1)
 }
+func (m FileHeaderMock) GetDownloadURL(ctx context.Context, path string, url url.URL, expires int64) (string, error) {
+	args := m.Called(ctx, path, url, expires)
+	return args.Get(0).(string), args.Error(1)
+}
 
 func TestFileSystem_Upload(t *testing.T) {
 	asserts := assert.New(t)
diff --git a/pkg/serializer/error.go b/pkg/serializer/error.go
index eec0ae2..f23d294 100644
--- a/pkg/serializer/error.go
+++ b/pkg/serializer/error.go
@@ -66,6 +66,10 @@ const (
 	CodeEncryptError = 50002
 	// CodeIOFailed IO操作失败
 	CodeIOFailed = 50004
+	// CodeInternalSetting 内部设置参数错误
+	CodeInternalSetting = 50005
+	// CodeCacheOperation 缓存操作失败
+	CodeCacheOperation = 50006
 	//CodeParamErr 各种奇奇怪怪的参数错误
 	CodeParamErr = 40001
 	// CodeNotSet 未定错误，后续尝试从error中获取
diff --git a/routers/controllers/file.go b/routers/controllers/file.go
index b1ad703..e9d651e 100644
--- a/routers/controllers/file.go
+++ b/routers/controllers/file.go
@@ -22,9 +22,9 @@ func DownloadArchive(c *gin.Context) {
 	ctx, cancel := context.WithCancel(context.Background())
 	defer cancel()
 
-	var service explorer.ArchiveDownloadService
+	var service explorer.DownloadService
 	if err := c.ShouldBindUri(&service); err == nil {
-		res := service.Download(ctx, c)
+		res := service.DownloadArchived(ctx, c)
 		if res.Code != 0 {
 			c.JSON(200, res)
 		}
@@ -137,13 +137,28 @@ func Thumb(c *gin.Context) {
 
 }
 
-// Download 文件下载
+// CreateDownloadSession 创建文件下载会话
+func CreateDownloadSession(c *gin.Context) {
+	// 创建上下文
+	ctx, cancel := context.WithCancel(context.Background())
+	defer cancel()
+
+	var service explorer.FileDownloadCreateService
+	if err := c.ShouldBindUri(&service); err == nil {
+		res := service.CreateDownloadSession(ctx, c)
+		c.JSON(200, res)
+	} else {
+		c.JSON(200, ErrorResponse(err))
+	}
+}
+
+// DownloadArchived 文件下载
 func Download(c *gin.Context) {
 	// 创建上下文
 	ctx, cancel := context.WithCancel(context.Background())
 	defer cancel()
 
-	var service explorer.FileDownloadService
+	var service explorer.DownloadService
 	if err := c.ShouldBindUri(&service); err == nil {
 		res := service.Download(ctx, c)
 		if res.Code != 0 {
diff --git a/routers/router.go b/routers/router.go
index b93b381..9ae811e 100644
--- a/routers/router.go
+++ b/routers/router.go
@@ -75,6 +75,8 @@ func InitRouter() *gin.Engine {
 				file.GET("get/:id/:name", controllers.AnonymousGetContent)
 				// 下載已经打包好的文件
 				file.GET("archive/:id/archive.zip", controllers.DownloadArchive)
+				// 下载文件
+				file.GET("download/:id", controllers.Download)
 			}
 		}
 
@@ -102,9 +104,9 @@ func InitRouter() *gin.Engine {
 			{
 				// 文件上传
 				file.POST("upload", controllers.FileUploadStream)
-				// 下载文件
-				file.GET("download/*path", controllers.Download)
-				// 下载文件
+				// 创建文件下载会话
+				file.PUT("download/*path", controllers.CreateDownloadSession)
+				// 获取缩略图
 				file.GET("thumb/:id", controllers.Thumb)
 				// 取得文件外链
 				file.GET("source/:id", controllers.GetSource)
diff --git a/service/explorer/file.go b/service/explorer/file.go
index be08ef6..970a18d 100644
--- a/service/explorer/file.go
+++ b/service/explorer/file.go
@@ -2,6 +2,7 @@ package explorer
 
 import (
 	"context"
+	model "github.com/HFO4/cloudreve/models"
 	"github.com/HFO4/cloudreve/pkg/cache"
 	"github.com/HFO4/cloudreve/pkg/filesystem"
 	"github.com/HFO4/cloudreve/pkg/filesystem/fsctx"
@@ -12,22 +13,24 @@ import (
 	"time"
 )
 
-// FileDownloadService 文件下载服务，path为文件完整路径
-type FileDownloadService struct {
+// FileDownloadCreateService 文件下载会话创建服务，path为文件完整路径
+type FileDownloadCreateService struct {
 	Path string `uri:"path" binding:"required,min=1,max=65535"`
 }
 
+// FileAnonymousGetService 匿名（外链）获取文件服务
 type FileAnonymousGetService struct {
 	ID   uint   `uri:"id" binding:"required,min=1"`
 	Name string `uri:"name" binding:"required"`
 }
 
-type ArchiveDownloadService struct {
+// DownloadService 文件下載服务
+type DownloadService struct {
 	ID string `uri:"id" binding:"required"`
 }
 
-// Download 下載已打包的多文件
-func (service *ArchiveDownloadService) Download(ctx context.Context, c *gin.Context) serializer.Response {
+// DownloadArchived 下載已打包的多文件
+func (service *DownloadService) DownloadArchived(ctx context.Context, c *gin.Context) serializer.Response {
 	// 创建文件系统
 	fs, err := filesystem.NewFileSystemFromContext(c)
 	if err != nil {
@@ -98,23 +101,56 @@ func (service *FileAnonymousGetService) Download(ctx context.Context, c *gin.Con
 	}
 }
 
+// CreateDownloadSession 创建下载会话，获取下载URL
+func (service *FileDownloadCreateService) CreateDownloadSession(ctx context.Context, c *gin.Context) serializer.Response {
+	// 创建文件系统
+	fs, err := filesystem.NewFileSystemFromContext(c)
+	if err != nil {
+		return serializer.Err(serializer.CodePolicyNotAllowed, err.Error(), err)
+	}
+
+	// 获取下载地址
+	downloadURL, err := fs.GetDownloadURL(ctx, service.Path)
+	if err != nil {
+		return serializer.Err(serializer.CodeNotSet, err.Error(), err)
+	}
+
+	return serializer.Response{
+		Code: 0,
+		Data: downloadURL,
+	}
+}
+
 // Download 文件下载
-func (service *FileDownloadService) Download(ctx context.Context, c *gin.Context) serializer.Response {
+func (service *DownloadService) Download(ctx context.Context, c *gin.Context) serializer.Response {
 	// 创建文件系统
 	fs, err := filesystem.NewFileSystemFromContext(c)
 	if err != nil {
 		return serializer.Err(serializer.CodePolicyNotAllowed, err.Error(), err)
 	}
 
+	// 查找打包的临时文件
+	file, exist := cache.Get("download_" + service.ID)
+	if !exist {
+		return serializer.Err(404, "文件下载会话不存在", nil)
+	}
+	fs.FileTarget = []model.File{file.(model.File)}
+
 	// 开始处理下载
 	ctx = context.WithValue(ctx, fsctx.GinCtx, c)
-	rs, err := fs.GetDownloadContent(ctx, service.Path)
+	rs, err := fs.GetDownloadContent(ctx, "")
 	if err != nil {
 		return serializer.Err(serializer.CodeNotSet, err.Error(), err)
 	}
 
 	// 设置文件名
 	c.Header("Content-Disposition", "attachment; filename=\""+fs.FileTarget[0].Name+"\"")
+
+	if fs.User.Group.OptionsSerialized.OneTimeDownloadEnabled {
+		// 清理资源，删除临时文件
+		_ = cache.Deletes([]string{service.ID}, "download_")
+	}
+
 	// 发送文件
 	http.ServeContent(c.Writer, c.Request, "", fs.FileTarget[0].UpdatedAt, rs)
 
diff --git a/service/explorer/objects.go b/service/explorer/objects.go
index 85d881b..24a5d09 100644
--- a/service/explorer/objects.go
+++ b/service/explorer/objects.go
@@ -61,7 +61,7 @@ func (service *ItemService) Archive(ctx context.Context, c *gin.Context) seriali
 		return serializer.Err(serializer.CodeNotSet, "无法解析站点URL", err)
 	}
 	zipID := util.RandStringRunes(16)
-	ttl, err := strconv.Atoi(model.GetSettingByName("local_archive_timeout"))
+	ttl, err := strconv.Atoi(model.GetSettingByName("archive_timeout"))
 	if err != nil {
 		ttl = 30
 	}